Glacial–interglacial organic carbon record from the Makassar Strait, Indonesia: implications for regional changes in continental vegetation

Abstract

Recent studies convincingly show that climate in the Western Pacific Warm Pool and other equatorial/tropical regions was significantly colder (by ∼3–4°C) during glacial periods, prompting a reexamination of the late Pleistocene paleoenvironments of these regions. This study examines changes in continental vegetation during the last two deglaciations (Terminations I and II) using a sediment core (MD9821-62) recovered from the Makassar Strait, Indonesia. Evidence based on the lignin phenol ratios suggests that vegetation on Borneo and other surrounding islands did not significantly change from tropical rainforest during the last two glacial periods relative to subsequent interglacial periods. This supports the hypothesis that the winter monsoon increased in strength during glacial periods, allowing Indonesia to maintain high rainfall despite the cooler conditions.